The Saskatchewan River (Cree: kisiskāciwani-sīpiy, "swift flowing river") is a major river in Canada, about 550 kilometres (340 mi) long, flowing roughly eastward across Saskatchewan and Manitoba to empty into Lake Winnipeg. Through its tributaries the North Saskatchewan and South Saskatchewan, its watershed encompasses much of the prairie regions of central Canada, stretching westward to the Rocky Mountains in Alberta and northwestern Montana in the United States. It reaches 1,939 kilometres (1,205 mi) to its farthest headwaters on the Bow River, a tributary of the South Saskatchewan in Alberta.[4]

The combined stream flows east-northeast, into Codette Lake formed by the Francois Finlay Dam at Nipawin then into Tobin Lake, formed by the E.B. Campbell Dam. It then flows northeast, passing through a region of marshes, where it is joined from the northwest by the Torch River and the Mossy River. At the northern edge of the marshes it flows east, twisting between a series of small lakes into west-central Manitoba to The Pas, where it is joined from the southwest by the Carrot River. Southeast of The Pas, it forms several streams in a delta on the northwest side of Cedar Lake, then exiting the lake on its southeast end and flowing approximately 5 kilometres (3 mi) to Lake Winnipeg, entering on the northwest shore north of Long Point. The waters of Lake Winnipeg eventually drain into Hudson Bay, via the Nelson River.

The river, like the province of Saskatchewan, takes its name from the Cree word kisiskāciwani-sīpiy, meaning "swift flowing river". The river and its tributaries provided an important route of transportation for First Nations and early Europeantrappers.

The river, labeled as the "Kish-stock-ewen" is identified on a Hudson's Bay Company map of 1760, produced from oral information from a First Nations man named Attickasish who had been Anthony Henday's guide. Another map from 1774 shows a fairly accurate course of the river.[9]

The Saskatchewan River and its two major tributaries formed an important transportation route during the precontact, fur trade, and early settlement periods in the Canadian West. In early fur trading days the South Saskatchewan tributary was known as "La Fourche des Gros Ventres" ("Fork of the Great Gorges") and the North Saskatchewan was known as "Rivière du Pas".

Fur trade on the lower river: The first European to ascended the river as far as the forks was Louis-Joseph Gaultier de La Vérendrye in spring 1739. The main posts on the river were (landmarks in parentheses): (Saskatchewan River Forks) Fort Le Jonquière (?), Fort de la Corne, Cumberland House, Saskatchewan, (The Pas):second Fort Paskoya, (inflow to Cedar Lake:) first Fort Paskoya and second Fort Bourbon, (Cedar Lake), (inflow to Lake Winnipeg:) Grand Rapids, Manitoba, and first Fort Bourbon. There were also a number of temporary posts that have left few records. By far the most important post was Cumberland House which was the depot for the route northwest to the rich Athabasca country. To the west, the North Saskatchewan had the greatest number of posts.